1. Field of the Invention
The present invention relates to an optical disc which stores an information signal and a reproduction device for such a disc. More specifically, the present invention relates to an optical disc which stores multimedia data including digital video data, audio data and sub-picture data as well as to a reproduction device for the disc.
2. Description of the Related Art
First Conventional Technique
Optical discs and the like have become an essential medium for the circulation and sale of music and video software. Users can enjoy the stored content of such recording media by purchasing discs at record shops and other retail outlets. In the present market, laser discs are widely used as the recording medium for image software while CDs (Compact Discs) are used as the recording medium for music software.
When optical discs are used as the storage media for image software, images are recorded onto a spiral track formed on the surface of the disc starting in the center and leading out towards the edge. By having images recorded in this way, the standard reproduction direction is the direction where following the spiral track results in movement from the inner periphery of the disc to the outer periphery, while the reverse reproduction direction is the direction where following the spiral track results in movement from the outer periphery of the disc to the inner periphery. The information recorded on the disc is read by rotating the disc in the standard reproduction direction and shining a laser beam onto the disc. In addition to the reproduction of the recorded information, other special kinds of reproduction such as xe2x80x9cfast forward reproductionxe2x80x9d and xe2x80x9crewind reproductionxe2x80x9d can be performed. Here, xe2x80x9cfast forward reproductionxe2x80x9d refers to reproduction in the standard reproduction direction which skips a certain number of units of the recorded information on the spiral track. xe2x80x9cRewind reproductionxe2x80x9d, meanwhile, refers to reproduction in the reverse reproduction direction which skips a certain number of units of the recorded information on the spiral track.
Once a user specifies fast forward reproduction, the optical pickup reads the recorded information from the spiral track in the standard reproduction direction while skipping a fixed amount of recorded information. On the other hand, once the user specifies rewind reproduction, the optical pickup reads the recorded information from the spiral track in the reverse reproduction direction while skipping a fixed amount of recorded information.
When the user is not interested in the output information, it is possible for the user to view such information in a short time by specifying fast forward reproduction. Conversely, by specifying rewind reproduction, a user gets another chance to view any data which they may have missed.
However, the kind of fast forward reproduction described above creates great problems for the developers of certain types of title. This is because the use of such reproduction can result in the user not viewing commercials inserted into movies recorded onto the optical disc.
In the field of image software, there is intense price competition. Since certain kinds of software titles, such as travel xe2x80x9cmooksxe2x80x9d (magazine books) or sales promotion titles, cannot achieve the high sales achieved by hit movies, the developers of such kinds of titles end up having to offer such titles at a low price or even provide them free. As a result, the developers of such titles often look to hotels, tour companies or airlines to sponsor the titles and so are forced to insert commercials for such sponsors into the images recorded on the title. However, even if the developer can find such sponsors and insert their commercials into the title, it is easy for the user to miss such commercials due to the use of fast forward reproduction.
Also, aside from commercial images, there are other images for which the viewing and understanding of the user are especially important to the title developer. For the example of a travel mook, such information may be travel regulations, behavioral standards of the destination, emergency contact numbers, or advice for how to cope with crime or accidents. Similarly, it may be necessary to properly inform the user of information in the image title which, if mistaken, could cause a lot of trouble, such as departure date, cost, cancellation regulations and the like. Despite the need to inform the user of this information, a user of a conventional system can, by specifying fast forward reproduction contrary to the wishes of the developer, all too easily skip such image content.
Second Conventional Technique
It would be no exaggeration to say that fast forward reproduction and rewind reproduction are xe2x80x9cclassicxe2x80x9d reproduction functions for optical discs. In recent years, the tendency of image software is for increased interaction, with interactive software being expected to become the norm. Here, a first substrate technique for interactive software is distributed recording. This refers not to the simple recording of an hour-long image onto the spiral track sequentially, but to the division of the image into ten or twenty-minute blocks which are recorded in a non-sequential order on a plurality of arcs of the track. A second substrate technique for interactive software is random reproduction where image information which is divided into a plurality of blocks is reproduced in a selected order according to several sets of control data. Such control data for random reproduction is composed of pairs of n retrieval order of the divided-up image blocks and address information specifying the arcs on the spiral track where the desired images are recorded. This control data can include several different combinations of retrieval orders, one of which is selected by the user and then reproduced. Once reproduction according to one set of control data is complete, the disc player provides the user with a display of several branch addresses for image reproduction using a menu or the like. Once the user has selected one of these branch addresses, the corresponding piece of control data is retrieved out of all of the control data and is used for image retrieval. By repeating this operation many times, switching can be achieved between a number of reproduction routes in accordance with the selections made by the user in response to the menu.
By using the first and second substrate techniques described above, interactive software for detective stories where the story can develop in a number of ways can be achieved.
It also becomes possible to achieve interactive image software such as goods catalogues, travel mooks, English conversation teaching materials or the like.
For the example of a travel mook, image information for a number of hotels, tourist spots, restaurants and sports facilities for, say, surfing or diving can be recorded on an optical disc. Here, by indicating their budget, interests and the like, a user can have image information for hotels and sports displayed in accordance with their indications.
However, if during the reproduction of the above example of interactive software, the user makes use of the classic fast forward reproduction function, there is a second problem in that the true value of the interactive software can be lost.
Again for the example of interactive software for a travel mook, suppose that reproduction routes in the shape of a tree with many branches are provided in addition to direct reproduction routes with no branches. In such a situation, the former reproduction routes are displayed to the user as a variety of courses using menus and so are highly interactive reproduction routes whose branch addresses are determined according to user confirmation operations. The latter reproduction routes are reproduction routes for digests which are made up of extracts of the most impressive material or material most likely to arouse the viewer""s interest.
The tree-like reproduction routes are determined by user selection. Here, a male tour conductor can be displayed on the screen to explain immigration procedures or any other difficult matters. Should the user be disinterested in such an explanation, they will specify fast forward reproduction. Such fast forward reproduction soon terminates the tour conductor""s explanation so that a course selection menu for xe2x80x9cCity coursexe2x80x9d or xe2x80x9cBeach coursexe2x80x9d appears on the screen. This menu display continues until a user selection is made, so that the reproduction does not advance. Since the user has skipped the tour conductor""s explanation, the user will not understand the content of the courses and will not be able to decide which course to select. Accordingly, the user will end up rewinding to the tour conductor""s explanation and, having properly listened to the explanation, make their selection. On selecting the xe2x80x9cCity coursexe2x80x9d, actual footage which shows discount retail outlets for women""s jewelry and cosmetics is shown. On showing no interest in such content, the user again specifies fast forward reproduction. Such fast forward reproduction soon terminates the shopping guide so that a course selection menu for xe2x80x9cBudget coursexe2x80x9d or xe2x80x9cGourmet coursexe2x80x9d is displayed on the screen. Here, had the user viewed the preceding images, the user would be sure to readily understand what is meant by the items xe2x80x9cBudget coursexe2x80x9d and xe2x80x9cGourmet coursexe2x80x9d, since this is the way in which travel mooks are edited by the title developer. However, by making fast forward reproduction operations after seeing only the opening information of a topic, the user can end up missing the explanation of such courses. As before, in order to make a correct selection from the menu, the user will end up rewinding to the footage of the discount retail outlets to hear the explanation.
Such use of fast forward when viewing interactive software ends up necessitating a troublesome rewind operation every time a menu is displayed, so that the user will end up hesitating before making a fast forward operation. Here, suppose that the user selects xe2x80x9cDigestxe2x80x9d the next time. This digest is a collection of the most impressive material or material most likely to arouse the viewer""s interest, with there being no harm in the user fast forwarding through its content. However, after experiencing the trouble of having to rewind every time a fast forward operation was made when viewing the branch routes, the user will end up hesitating before making a fast forward operation. Here, even if this digest includes a shopping guide which introduces discount retail outlets of women""s jewelry and cosmetics or other such material which the user has already seen, the user will still end up persevering through such content without fast forwarding.
For the situation described above, it is clear that the user should feel free to fast forward through the digest image route which contains no branches and that the user should not skip through reproduction routes which contain many branches. On performing such skip reproduction, the user ends up having to terminate the skip reproduction whenever there is a menu and make a rewind operation to hear the explanation of the selection items in the menu. This kind of reproduction is highly inefficient.
In order to overcome such a situation, it may be better to have an automatic selection of a branch address when the user has skip reproduction performed. By doing so, since the tour conductor""s explanation and the menu can be instantaneously reproduced, the user can easily make a menu selection. However, by advancing to the next course by means of such fast forward reproduction, it becomes difficult to know where a current reproduction position is in the entire construction of the route. Here, if a variety of scenes are displayed on the screen, it becomes difficult for the user to grasp what a present scene is, how this scene was arrived at, or at what position in the reproduction route a user is presently situated.
From the point of view of the title developer, if such skip reproduction is achieved through automatic branches, the developer will end up putting all of their energy into the development of the story by focusing on the position of the menus and branches, which means that the developer may not get the proper message across to the user. By setting such automatic branches, the title developer can end up losing sight of their original intentions for the software title.
In view of the stated problems, it is a primary object of the present invention to provide an optical disc and reproduction device which will definitely display to the user information, such as commercials, regulations and contracts, which is regarded as important by the title developer.
It is a second object of the present invention to provide an optical disc and reproduction device which, while preventing the execution of special reproduction functions when it would destroy the value of the interactive software, still enables a user to make valid use of such special reproduction functions.
The first object of the present invention can be achieved by a multimedia optical disc comprising a data area including an object recording area which includes a plurality of sub-areas, wherein each of the plurality of sub-areas stores a plurality of blocks each of which includes moving picture data and management information, wherein the management information of each block is effective in a reproduction apparatus during an effective time, the effective time being a time period during which the moving picture data in the same block as the management information is reproduced, wherein the management information of each block includes user operation limitation information indicating whether user operations are limited during the effective time.
By means of the stated construction, management information which is only valid during the reproduction period of the video data in the block in the object is provided. User operation limitation information is provided in this management information and stipulates whether special reproduction features such as fast forward or rewind are permitted, so that during the reproduction of images such as commercials, travel contracts and the like, fast forward operations can be prohibited, while such fast forward operations can be permitted for sections of video data which do not contain such essential content. By doing so, the activation of interruption processing for such special reproduction dynamically switches between being permitted and being prohibited depending on the content of the video data.
Here, each of the plurality of sub-areas may extend over a plurality of consecutive sectors.
The plurality of sub-areas may be aligned in a rotation direction of the multimedia optical disc in an order whose moving picture data is reproduced.
Each piece of the management information and each piece of moving picture data may be recorded in a sector.
The second object of the present invention can be achieved by a multimedia optical disc comprising a data area and an index area, the data area comprising an object recording area which stores at least an object and includes a plurality of sub-areas, wherein each of the plurality of sub-areas stores a plurality of blocks each of which includes moving picture data and management information, and the index area comprising a first index area for storing a plurality of pieces of route information each of which includes a sequence of addresses of objects; wherein alignments of the sequence of addresses of objects in the plurality pieces of route information represent the plurality of reproduction orders, and a second index area for storing a plurality of pieces of user operation limitation information which respectively correspond to the plurality of pieces of route information, wherein each of the plurality of pieces of user operation limitation information sets a limit to user operations, wherein each piece of user operation limitation information is effective during a reproduction of objects specified by the alignments of the sequence of addresses (hereinafter objects specified by an alignment of the sequence of addresses are called a chain).
By means of the construction described above, for ten or twenty-minute periods during which a group of objects specified by a list of addresses are reproduced, the user can manipulate a remote controller and so give a signal for a key interrupt for special reproduction. The determination of whether the interrupt processing for this special reproduction is permitted or not is then made based on the user operation limitation information which corresponds to this list of addresses. Here, by setting the user operation limitation information so that the activation of interrupt processing for special reproduction is prohibited for route information for highly interactive reproduction routes whose branch addresses are interactively selected by users, the activation of key interrupts for special reproduction, such as rewind and fast forward, made by a user who is ignorant of the highly interactive nature of the content can be prohibited. By prohibiting the activation of key interrupts for special reproduction for highly interactive reproduction routes which contain interactive branches, execution of special reproduction which would damage the interactive nature of a title can be prevented.
On the other hand, route information for reproduction routes which have an image content to be viewed consecutively, such as a digest version, can be set so that its user operation limitation information permits the execution of interrupt processing for special reproduction. By doing so, when a user depresses a key, interrupt processing for special reproduction, such as rewind and fast forward, can be activated. By allowing the activation of key interrupt processing for special reproduction in such reproduction routes which are designed to be viewed according to the user""s wishes, the reproduction routes for such video digests can be viewed using such special reproduction. Accordingly, the benefits of such special reproduction can be achieved for the reproduction routes for such video digests.
Here, multiplexed several pieces of moving picture data, each of which includes an angle identifier, may be recorded in a certain area of the object recording area, wherein the management information of the certain area may include addresses of the multiplexed several pieces of moving picture data, wherein each piece of the user operation limitation information may include a mask flag indicating whether to mask a key interrupt of an angle identifier change when a key is pressed to request the key interrupt.
By means of the stated construction, on the one hand first management information provides information for the switching of the address of the optical pickup, while on the other hand the second management information includes user operation limitation information which prevent the activation of interrupt processing for key interrupts made by the user. By doing so, while providing objects with a control mechanism for special reproduction, a second control mechanism can be achieved for the reproduction device which can prevent such activation from the reproduction route side. By setting the user operation limitation information on the reproduction route side in such a two-sided control mechanism, the title developer is free to pass the object side control to a desired level over to the user. By making such settings, reproduction routes which can fully achieve interaction, as well as xe2x80x9cdemonstrationxe2x80x9d reproduction routes where an interactive control content may partially or entirely achieved can be recorded on the same optical disc so that depending on the manner of the reproduction of the disc, a desired switching between these kinds of reproduction routes can be achieved.
Here, at least one block in the object recording area may include any of moving picture data and sub-picture data for illustrating a menu including a plurality of items which visually presents contents of an interactive control, wherein the management information of said block may include cursor operation information for switching an item to a first display state based on a cursor key operation made by the user, determination operation information for identifying for switching an item to a second display state based on a determination key operation made by the user, and a plurality of commands each of which specifies an interactive control corresponding to an item determined by the determination operation, wherein each of the plurality pieces of user operation limitation information may include a mask flag indicating whether to mask a key interrupt of the interactive control when the user requests the key interrupt by using any of the cursor key operation and determination operation.
By means of the stated construction, while on the one hand information for receiving cursor operations and confirmation operations is provided in the management information, on the other hand the activation of interrupt processing for key interrupts by the user can be prevented by user operation limitation information provided in the second management information. By doing so, even though a control mechanism for cursor operations and confirmation operations is provided on the object side, a second control mechanism for preventing the activation of such operations is provided to the reproduction route side. By setting the user operation limitation information on the reproduction route side in such a two-sided control mechanism, the title developer is free to pass the object side control to a desired level over to the user. By making such settings, reproduction routes which can fully achieve interaction, as well as xe2x80x9cdemonstrationxe2x80x9d reproduction routes where an interactive control content may partially or entirely be achieved can be recorded on the same optical disc so that depending on the manner of the reproduction of the disc, a desired switching between these kinds of reproduction routes can be achieved.
Here, at least one block may include at least one of a plurality pieces of audio data and a plurality pieces of sub-picture data, wherein each piece of audio data and each piece of sub-picture data may specify a channel identifier, wherein the mask flag may indicate whether to mask a key interrupt of a channel change for one of audio data and sub-picture data when a key is pressed to request the key interrupt.
By means of the stated construction, whilst providing a plurality of channels for the audio data and sub-picture data, the user operation limitation information in the second management information can prevent the activation of interrupt processing for the switching of such channels according to a key interrupt made be a user operation. In this way, a two-sided control mechanism is achieved whereby even when a channel switching mechanism is provided on the object side, the activation of such an operation can be prevented on the reproduction route side. By setting the user operation limitation information on the reproduction route side in such a two-sided control mechanism, the title developer is free to pass the object side control to a desired level over to the user. By making such settings, reproduction routes which can fully achieve interaction, as well as xe2x80x9cdemonstrationxe2x80x9d reproduction routes where an interactive control content may partially or entirely achieved can be recorded on a same optical disc so that depending on the manner of the reproduction of the disc, a desired switching between these kinds of reproduction routes can be achieved.